A press-fit terminal including a board connecting portion to be press-fit and connected to a through hole provided in a printed circuit board (PCB) is formed with a tin plating layer on a surface of the board connecting portion in many cases. If the tin plating layer of the press-fit terminal is scraped during insertion into the through hole, scraped tin (scrapings) possibly affects electrical connection between the press-fit terminal and the through hole, a circuit on a printed circuit board and the like.
Accordingly, in terms of suppressing the scraping of a metal layer on a surface of a board connecting portion of a press-fit terminal, improvements have been made for the composition of the metal layer and the shape of the board connecting portion. As an improvement for the composition of the metal plate, it is, for example, disclosed in patent literature 1 to successively provide a Cu3Sn alloy layer and a Cu6Sn5 alloy layer on a surface of a base material of a press-fit terminal via a plating underlayer and eliminate the exposure of Sn on a surface of the Cu6Sn5 alloy layer. By providing two types of alloy layers, scraping during press-fitting into the through hole is reduced, utilizing a hardness increase on the base material surface side.